Mitutoyo SJ-210 - REFERENCE INFORMATION; Roughness Standard

No.99MBB122A
18-1
18 REFERENCE
INFORMATION
In this chapter, the surface texture standard and the surface texture parameters are
explained.
18.1 Roughness Standard
18.1.1 Evaluating based on JIS B0601-1982
■ Standard cut-off values and evaluation lengths for Ra (Use the 2CR filter.)
Ra Range Cut-off value (λc) Evaluation length (ℓn)
Ra ≤ 12.5 µm 0.8 mm 2.4 mm or more
12.5 < Ra ≤ 100.0 µm 2.5 mm 7.5 mm or more
■ Standard cut-off values and evaluation lengths for Ry
Ry Range Sampling length (ℓ)
Ry ≤ 0.8 µm 0.25 mm
0.8 < Ry ≤ 6.3 µm 0.8 mm
6.3 < Ry ≤ 25.0 µm 2.5 mm
25.0 < Ry ≤ 100.0 µm 8 mm
100.0 < Ry ≤ 400.0 µm 25 mm
■ Standard cut-off values and evaluation lengths for Rz
Rz range Sampling length (ℓ)
Ry ≤ 0.8 µm 0.25 mm
0.8 < Ry ≤ 6.3 µm 0.8 mm
6.3 < Ry ≤ 25.0 µm 2.5 mm
25.0 < Ry ≤ 100.0 µm 8 mm
100.0 < Ry ≤ 400.0 µm 25 mm